The hammer looks great, but to (perhaps) clarify what Loriel is saying: you have the sprites drawn so that when playerdir == 0 or 2, the player will be swinging the hammer side to side like a sword. But the hammer is massive! (the reason it looks great) Anything that heavy, swung that way, is gonna spin the player around in a circle while his hammer and forearms go flying off in some random direction.
I'm picturing a vertical swing. For playerdir == 1 and 3, your sprites look great for that (although a bit more 3d would be cool). For north and south, you might want to edit them a wee bit.
However, gfx rating = 10/10